Funding for this research was provided by:
National Natural Science Foundation of China (31872475)
Agriculture Research System of China (CARS-42-17)
Sichuan Veterinary Medicine and Drug Innovation Group of China Agricultural Research System (CARS-SVDIP)
Sichuan Province Research Program (2017JY0014)
Received: 7 August 2019
Accepted: 11 November 2019
First Online: 26 November 2019
Ethics approval and consent to participate
: The study was approved by the Animal Ethics Committee of Sichuan Agricultural University (approval No. XF2016–17).
: Not applicable.
: The authors declare that they have no competing interests.